سنتز و بررسي ، خواص فيزيكي-مكانيكي و تخريب پذيري داربست هاي متخلخل پلي ﴿گليسيرول-سباسات﴾ ﴿PGS )به روش الكتروريسي براي كاشت سلول هاي بنيادي شبكيه چشم

چكيده انگليسي :

74 Synthesis and Characterization of Physico Mechanical Properties andDegradation Behavior of Porous Poly glycerol sebacate PGS Scaffold for Retinal Stem Cell Using Electerospinning Technique Maryam Paydar m paydar@ce iut ac ir Date of Submission2014 7 22 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Saied Nouri Khorasani saied@cc iut ac irAbstractHuman body in spite of having high capability of regeneration can be damaged severely In youth regeneration of the damaged tissues is easily done But in higher ages this ability degrades So many oldpeople or young ill ones have the dream of replacing their damaged tissues with fresh ones Nowadays withthe advancements in medical science and introducing biomaterial engineering this dream isachievable Tissue engineering is a combination of material biology and engineering science that introducesthe relation of biological tissues in order to make advancements in tissue repair and regeneration A bio scaffold can be broadly defined as a structure used to repair and regenerate damaged tissue throughthe cell migration into the defect site The scaffold can be made from natural or synthetic materials Manytypes of polymers natural and synthetic are widely used in research associated with human retinal eyedisease Poly glycerol sebacate PGS is a degradable polyester which is synthesized through apolycondensation reaction of glycerol and sebacic acid under high temperature and vacuum Its degradationproducts of hydrolysisare nontoxic and undergoes natural metabolites These properties make PGS a goodcandidate for cornea and retina tissues repair In this thesis the PGS prepolymer was synthesized bypolycondensation of equimolar glycerol and sebacic acid at 120 C under nitrogen atmosphere for 24 h Then synthesized prepolymer was dried at 50 oCunder vacuum 200 mbar Therefore a viscous andtransparent prepolymer was obtained which can be dissolved in different solvents Thereafter polymercharacterization was carried out using FTIR X ray and DSC The results showed that the synthesizedpolymer has the properties similar to PGS that was synthesized in previously published literature At thenext step in order to perform electrospining of the prepolymer solutions PGS with different ratios ofgelatin in asetic acid were prepared and electrospinning was performed in various time periods of thespinning electric voltage and flow rate Finally spinning distance of 15 cm electric voltage of 13 5 kv andflow rate of 0 6 ml min was selected and electrospinning of the solution with ratio of 1 1 PGS and Gelatinin acetic acid solvent 30 v was performed SEM and optical microscope images shown that fiberswithout any bead are obtained Degradation analysis showed that after 30 days the weight loss of thesamples immersed in phosphate buffer solution was only 40 The mechanical measurements indicated thattensile modulus of nanofiber web is 0 1 MPa approximately equal to that of the retina tissue Porosity andwater absorption ratio of the nonofiber web was obtained to be 80 and 30 respectively It can bededuced from the MTS results that at the first day the cells have better adherence property than the instancesample Observations demonstrate that there is no evidence of toxicity or impurity in the sample polymerscaffold So for the first time a porous scaffold of PGS and gelatin is obtained using electrospinningmethod witch has proper specifications for tissue engineering of retina Key WordsCondensation polymerization poly glycerol sebacate electerospinning retina tissue engineering

پايدار، مريم

سنتز و بررسي ، خواص فيزيكي-مكانيكي و تخريب پذيري داربست هاي متخلخل پلي ﴿گليسيرول-سباسات﴾ ﴿PGS )به روش الكتروريسي براي كاشت سلول هاي بنيادي شبكيه چشم

پليمريزاسيون تراكمي , مهندسي بافت